o,p,q,r = [float(i) for i in input().split()]
print(format(((q-o)**2+(r-p)**2)**(1/2), '.8f')) float(i) for i in input().split() for i in input().split() i input().split() ().split () input split for i in input().split() float(i) float i o,p,q,r = [float(i) for i in input().split()] o [float(i) for i in input().split()] p q r print(format(((q-o)**2+(r-p)**2)**(1/2), '.8f')) print format(((q-o)**2+(r-p)**2)**(1/2), '.8f') format ((q-o)**2+(r-p)**2)**(1/2) (q-o)**2+(r-p)**2 (q-o)**2 q-o q o 2 (r-p)**2 r-p r p 2 1/2 1 2 '.8f' q,r = [float(i) for i in input().split()] [float(i) for i in input().split()] q p,q,r = [float(i) for i in input().split()] [float(i) for i in input().split()] p o,p,q,r = [float(i) for i in input().split()] [float(i) for i in input().split()] o r = [float(i) for i in input().split()] [float(i) for i in input().split()] r
o,p,q,r = [float(i) for i in input().split()]
print(format(((q-o)**2+(r-p)**2)**(1/2), '.8f'))